function results=ConstructElementb(perEln,f,coordinates)
    matrix=[[1,coordinates{1}(1),coordinates{1}(2)];
            [1,coordinates{2}(1),coordinates{2}(2)];
            [1,coordinates{3}(1),coordinates{3}(2)]];
    delta=1/2*det(matrix);
    be=zeros(perEln,1);
    for m=1:perEln
        be(m)=delta*f/3;
    end
    results=be;
end
